Speed-governor



(No Model.)

R. MOKENNA.

SPEED GOVBRNUR. No. 342,623.

Patented May 25, 1886.

UNITED STATES `ATENT' Ormea.

ROBERT MCKENNA, OF VHITE, TENNESSEE.

SPEED-GOVERNOR.

SPECIFICATION forming part of Letters Patent No.342,623, dated May 25,1886.

A pplicaton filed November 2D, 188,5. Serial No. 183,436. (No model.)

To all whom t may concern.-

Be it known that I, ROBERT MCKENNA, a citizen ofthe United States,residing at Vhite, in the county of Shelby and Stateof Tennessee,

5 have invented new and useful Improvements in Duplex BallSpeed-Governors, of which the following is a specification.

My invention relates to an improvement in speed-governors forsteam-engines; and it conio sists in the peculiar construction andcombination of devices that will be more fully set forth hereinafter,and particularly pointed out in the claims.

In the drawings, Figure l is a vertical seci 5 tional View of -aspeed-governor embodying my improvements. Fig. 2 is an enlargeddetailview. Fig. 3 is a detailed sectional view.

A represents a suitable frame, and B represents a driving-shaft, whichis journaled horizontally in the said frame.

V represents a vertical hollow shaft, which is journaled in the frame A,and provided at its lower end with an enlarged head and at its upper endwith a collar, '1 and thereby preA 2 5 vented from moving vertically inthe frame.

On the lower portion of the shaft V is an enlarged sleeve, D, and on theupper portion of said shaft is a similar sleeve, D, the said sleevesbeing journaled at their upper and lower ends in the frame and free torotate independently of the shaft V. The latter has a drum, k, on itslower portion in the sleeve D, and a similaidrum, k2, on its upperportion in the sleeve D?, and has its lower end provided with aninterior screw-thread, X.

To the inner end of the shaft B is secured a miter-pinion, C, whichmeshes with a similar wheel, C, fixed on the upper end of the sleeve D,and with a similar pinion, G2, fixed on the 4o lower end of sleeve DZ.By this construction it will be readily seen that the sleeves arerotated in opposite directions on the shaft V when the shaft B isturned.

The sleeves are provided with studs O and 02,' which project from theirouter sides, andy also with openings in their sides, which alignvertically with the studs. 1

To the studs O are fulcrumed lever-arms E, which carry the usualgovernor balls or 5o weights, F, and similar arms, E, carrying balls F2,are fulcrumed to the studs O2.

I and P2 represent iieXible straps, which envadapted to lit in thehollow shaft V, and is provided with a screw-thread that iits the threadX in the interior of the said hollow shaft.

The lower portion of this said valve-governor stem is angular and worksin a guide, T, and

is connected to a valvelink, XV, by a pitman,

R, as at s and fr. The link W is connected to the throttle-valve of thesteam-engine by 7o means of any suitable and well-known devices, whichare not shown, nor more particularly described herein, as they form nopart of my invention.

On the stem M are placed bearingsprings h, which bear between washers h'that are immovable on the stem and washers h2 that are free to slideupon the stem, against the pressure of the springs, as shown in Fig, 3.

The operation of my invention is as follows: 8o Vhen the engine is inmotion at the desired speed, the balls F and F2 swing at such anelevation as will canse the exible straps to loosely encircle thefriction-drums, thereby permitting the latter, and therefore the hollowshaft, to remain stationary. Vhen the speed of the engine increases, theballs F rise, and canse the strap P to tightly embrace the drum k,thereby locking the shaft V to the sleeve D and causing said shaft torotate. Its 9o screw-thread working on the'threaded portion of the stemM, causes the latter to descend, and thereby partly close thethrottlevalve, and thus diminish the quantity of steam supplied to theengine. When the stem M reaches the limit of its movement in eitherdirection, its thread passes the thread X in the hollow shaft, andthereby becomes disengaged therefrom. If the threaded portion of thestem vwere permitted to remain permanroo ently disengaged from thethreadin the hollow shaft, the governor would cease to operate. To preventthis, the springs h on the stem M have been devised. When the threadedporre-cngage the threaded portion of the hollow shaft when the motion ofthe latter is reversed, as will be very readily understood.

When the engine runs too slowly, the balls F2- descend and cause thestrap P to tightly embrace the drum k2, and thereby rotate the shaft Vin the contrary direction, raise the stem M, and open the throttle widerto admit more steam to the engine, as will be readily understood. f

I claim* 1. The combination of the shaft V, the valvestem M, meansconnecting the latter with the 'shaft V, whereby itwill be moved whenthe said shaft rotates, the sleeves rotating on the shaft in oppositedirections and carrying the fnlerumed weighted governor-arms, and theflexible straps encircling the shaft V, and having their ends connectedto the governorarms, for the purpose set forth, substantially 3o asdescribed.

2. The combination, in a duplex ball speedgovernor, of ahollow shaft, V,having athread, as, on its inside surface, and friction-drums k and la?,secured on its outside, with arms E and E, having flexible bands l? andP attached to their inner ends, said flexible bands being adapted toencircle, embrace, and turn frictiondrums k and k2, substantially as andfor the purpose set forth.

3. The combination, in a duplex ball speedgovernor, of avalve-moving1ink,W, and aconnecting-link, R, with a threaded valve-stem,M, having a part of its length made so as to adapt it to slide up anddown in a guide, T, ahollow shaft, V, havingathread, X, on itsinsidesurface, and friction-drums k and k", secured on its outside, and arms Eand E', having flexible bands P and P2 attached to their inner ends,`allsubstantially as set forth.

ROBERT MCKENN A.

litnessesz D. L. RERsoN, JNO. B. HILL.V

